As of 2011, in Japan, the number of patients with chronic renal failure has exceeded 300,000 (Non-Patent Document 1). Among them, only less than a few percent of all patients can receive kidney transplants, and the survival of most patients with renal failure depends on the blood purification method, including hemodialysis.
Hemodialysis requires a large amount (equal to or more than 120 L) of water per patient, and electricity to allow the operation of the equipment. For this reason, fully equipped infrastructure facilities of water and electricity are required for the hemodialysis.
Further, for the dialysis patients, the burden in terms of the number of hospital visits (three times a week), the treatment time (four hours per treatment), and the like in association with the hemodialysis is very heavy. Thus, without a fully operational transportation infrastructure, it is impossible to visit a hospital and receive a dialysis treatment as frequent and as long as described above, which is a problem. Furthermore, similar problems also arise in an emergency where the lifelines are cut off.
Patients with renal failure develop acute uremia when the above-mentioned dialysis treatment is not sufficient. Acute uremia can be dealt with by quickly removing uremic toxins and excess water from the body as an emergency treatment. However, since conventional therapeutic methods for acute uremia involve diffusion and filtration as the main principles, in an environment where the infrastructure and the like are not fully operational, it has been difficult to provide an emergency treatment.
In addition, adsorption columns used in the direct hemoperfusion method or plasma adsorption can selectively eliminate disease-causing substances without requiring a substitution fluid or dialysate. However, the adsorption columns greatly stimulate the blood, and the use of anticoagulant is unavoidable, which has been a problem.
These problems greatly reduce the quality of life (QOL) of dialysis patients.
Based on such a situation, the development of novel medical materials excellent in blood compatibility has been desired which can be used even in an environment where the infrastructure and the like are not fully operational.
It should be noted that there has been a report on excellent blood compatibility of EVAL fibers (blood cell inactivation (Non-Patent Document 2), coagulation system inactivation (Non-Patent Document 3)).
In addition, there are about 100 types of uremic toxins, and of these uremic toxins, creatinine is present in the normal human blood at a concentration of less than 100 μM. However, in the case of dialysis patients, the creatinine level in the blood may become approximately 1,200 μM, and it is required to quickly remove creatinine in particular (Non-Patent Document 4).